Grade measuring attachment for carpenters&#39; or builders&#39; levels



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GRADE MEASURING ATTACHMENT FOR CARPENTERS OR BUILDERS LEVELS Filed April 1, 1954 w !IHHIIII|"" m WN ,V INVENTOR.

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United States Patent 2,746,164 GRADE MEASURING ATTACHMENT FOR CAR- PENTERS R BUEDERS LEVELS William C. H. Eitzen, West Englewood, N. J. Application April 1, 1954, Serial No. 420,375 1 Claim. (Cl. 33-214) This invention relates to carpenters or builders levels, and the main object is the provision of a readily attachable or removable grade or slope measuring attachment on one end of the level, so that the grade may be immediately read in inches per foot or in any other desired linear units. The invention is applicable in many jobs, obviously too numerous to be mentioned, but as a single example the laying of concrete or masonry in the construction of walls, sidewalks, floors, or the like may be cited.

Another object of the invention is the provision of an attachment for levels for the purpose mentioned, which is simple in construction and operation and inexpensive in cost of manufacture.

The above broad as well as additional and more specific objects will be clarified in the following description wherein characters of reference refer to like-numbered parts in the accompanying drawing. It is to be noted that the drawing is intended solely for the purpose of illustration and that it is therefore neither desired nor intended to limit the invention necessarily to any or all of the exact details of construction shown except insofar as they may be deemed essential to the invention.

Referring briefly to the drawing, Fig. l is a perspective view of the attachment embodying the present invention, shown attached to a level, the latter being drawn in phantom.

Fig. 2 is a sectional view taken on the line 22 of of Fig. 1.

Fig. 3 is a laid out pattern of the material, preferably sheet metal possessing a degree of resiliency, out of which the supporting frame of the device is shaped.

Fig. 4 is a side elevational view of a level equipped with the present attachment, illustrating how the combination may be used to measure a grade.

Referring in detail to the drawing, the numeral indicates or represents any conventional level, to either end of which the present attachment may be applied.

The attachment comprises a frame 11 which may be formed out of the pattern 11a shown in Fig. 3. The frame comprises a back 12 adapted to engage the end wall 13 of the level, the horizontally spaced pair of identical ears 14 having aligned holes 15 therethrough, the rearwardly extending vertically spaced horizontal yieldable clamp jaws 16, and the index finger or indicator 17 spaced forward from and parallel with the back 12. The parts of the pattern 11a from which the parts of the frame, just indicated, are formed by obvious suitable bending, are indicated by the same reference numerals followed by the suflix a.

A shaft 18 is rotatably supported in the holes 15 of the ears 14, having a turn knob 19 on one end and having keyed thereto between the ears a pinion 20. A rigid strip, having its face graduated in a linear scale, shown at 21, and provided with rack teeth 22 over the greater portion of its length, is slidably mounted against the back 12 with the rack 22 engaged by the pinion 20. The indicator 17 is spaced forward from the back 12 a sufficient distance, through the medium of the support or base 27 between the back 12 and the indicator, to enable the strip or rule 21 to slide between the indicator and the back, whence the indicator, which is flat as shown, provides also a guide to confine the rule to sliding movement within its own plane.

It is apparent from the disclosure thus far, that by rotating the knob 19 the rule may readily be raised or lowered to accommodate the level to a true horizontal position on a slope, as illustrated in Fig. 4.

In order to automatically but releasably lock the rule 21 in the downwardly extended position to which it has been moved by the pinion 19 to meet the slope, as shown in Fig. 4, the following additional means is provided. An L-shaped pawl 23 has a hole 24 in its arm 25, through which the shaft 18 passes and thus rotatably supports the pawl, which is positioned between the knob 19 and the adjacent ear 14, with the pawl tooth 26 extending inward over the rack 22. A coiled spring 28 has its intermediate portion coiled about the shaft 18 between the knob 19 and the pawl arm 25. The ends of the spring 28 constitute legs 29 and 30; the leg 29 has a deformed extremity resting and pressing against the pawl arm 25 near the lower end of the arm, and the leg 30 has a similar deformed extremity anchored in an opening through the adjacent frame ear 14. Thus, the pawl arm 29 is normally urged down against the base of the ear 14 to normally urge the pawl tooth 26 into engagement with the rack 22. Upon rotation of the knob 19 clockwise, Fig. 1, the pinion moves the rule downward and in so moving the rack teeth successively push the tooth 26 outward and the spring returns it successively to the notches between the rack teeth. The tooth, however, resists outward movement from the rack when upward movement of the rule is attempted, or, in other words, it will support the end of the level, as shown in Fig. 4, in its extended position. Thus, knowing the length of the level, the grade of the slope can be read right off the rule, by noting the linear distance shown at the indicator 17, in inches per foot.

Obviously, modifications in form or structure may be made without departing from the spirit or scope of the invention.

I claim:

A grade measuring attachment for an elongated member having horizontal top and bottom walls and a vertical end wall, comprising a frame, said frame including a back adapted to set against said end wall, said back having vertically spaced resilient horizontal jaws extending rearward from said back adapted to frictionally engage said top and bottom walls and thus clamp the frame to the end of the member, said back having horizontally spaced ears extending forward therefrom substantially at right angles thereto, said ears having aligned openings therethrough, a shaft rotatably mounted in said openings and having one end thereof extending a distance beyond the adjacent ear, said end of said shaft having a turn knob thereon, said shaft having a pinion thereon between said ears, a graduated rigid strip slidably mounted against said back and having a rack thereon engaging said pinion whereby rotation of said knob moves said strip vertically, a pawl rotatably mounted on said shaft between said adjacent ear and said knob, and an elongated spring having the intermediate portion thereof coiled about said shaft, one end of said spring being anchored in said adjacent ear, the other end of said spring engaging said pawl and urging the same into engagement with said rack thereby releasably locking said strip against retraction in the downwardly extended position of the strip.

References Cited in the file of this patent UNITED STATES PATENTS 143,942 Thornley Oct. 21, 1873 310,048 Grams Dec. 30, 1884 986,924 LHeureux Mar. 14, 1911 1,305,636 Weilep June 3, 1919 1,346,619 Weathersby July 13, 1920 2,520,700 Thorndyke Aug. 29, 1950 

